1. Field of the Invention
The present invention relates to a pointing device, and more particularly to a pointing device used for a terminal having a touch screen and a method for using the same.
2. Description of the Related Art
Among conventional methods for inputting letters in a mobile terminal using a touch screen, a soft keyboard method refers to a method of inputting letters by displaying an input window in the form of a keyboard on a touch screen. Pen-clicks may be inputted thereon in order to solve a problem relating to portability of a keyboard and a mouse of a mobile terminal. Currently, such touch screens have been used for various terminals, such as cellular phones, smart phones, automatic teller machines (ATMs), palm PCs, personal digital assistants (PDAs), etc., as input apparatuses. In particular, examples of mobile terminals having such touch screens are electronic notebooks, cellular phones, PDAs, etc.
Conventionally, a touch screen provides an interface allowing a user to input a command and information to a terminal by touching a finger or a stylus pen to an icon displayed on the touch screen, mobile terminals have become smaller having light weight, so these touch screens must be miniaturized with light weight corresponding to that of the mobile terminals. Accordingly, mobile terminals such as a PDA, etc., provide a user interface through an image on a touch screen as a substitute for a keyboard. If necessary, a stylus pen may be used to activate the keyboard.
A soft keyboard on a screen is displayed as shown in FIG. 1 in order to input letters on a touch screen miniaturized as described above. FIG. 1 shows a screen used according to a conventional soft keyboard input method. In the soft keyboard input method, since all keys of a keyboard must be displayed on a screen of a mobile terminal, an area assigned for each key button is very small. For example, in a PDA having a screen of 3.5 inches, an area of each key button is about 4×4 mm. Also, in currently-used mobile terminals, all keys for inputting letters are displayed on a miniaturized touch screen as a soft keyboard.
Therefore, a screen for displaying a keyboard for inputting letters must be larger. Consequently, the size of a section for displaying outputted letters must be reduced. Also, since all icons having various functions must be displayed on the same screen, the size of a section for displaying each icon is reduced. Accordingly, an assistance tool can be required in order to input letters or select icons displayed on a screen. The assistance tool may include a stylus in the form of a writing instrument having a sharpened tip part. A user can carry the stylus or the stylus can be fixed on a rear side of a terminal body to allow the user to easily locate and use the stylus.
However, currently-used touch screens are very small and have very slippery surfaces. Therefore, when using a stylus pen on a touch screen, unintended commands may be executed due to the stylus slipping to an unintended command or selection on the slippery surface of the touch screen. Accordingly, inconvenience may occur in that a user must re-input an intended command. In other words, when performing an operation requiring accurate pointing through a mobile terminal having a touch screen, it is difficult to accurately select intended icons or letters without using assistance tools such as a stylus, etc.
As described above, conventionally, when a user inputs letters, etc., through a touch screen by using a finger without using an assistance tool such as a stylus, since the user presses small buttons of a keyboard displayed on a miniaturized touch screen, the user may mistakenly press unintended buttons next to intended buttons. Accordingly, inconvenience is incurred, in that the intended buttons must be re-inputted. That is, if an area of a finger touching a touch screen is wider than areas of displayed icons, etc., it is impossible to accurately point to the displayed icons. Accordingly, problems are incurred, in that unintended icons being frequently inputted.
Accordingly, if a user is not using a stylus, the user must use his/her finger to touch a screen by repeatedly performing trial and error until an intended operation is achieved. Also, if the user performs an operation by frequently using assistance tools such as an automatic pencil, etc., a problem is incurred in that a surface of a screen may be damaged.